The following block diagram shows the different building blocks of a cloud that are normally seen in a private implementation with a commercial orchestrator:

A private cloud with a commercial orchestrator

As we can see, in this private cloud setup, additional blocks such as Self Service Portal, Metering & Billing, and Workflows & Connectors sit on top of an already existing virtualized environment to provision a virtual machine, a stack of virtual machines, or a virtual machine with some application installed and configured over it.

While most of the commercial orchestrators are extensible, some of them have prebuilt plugins or connectors to most commonly used enterprise toolsets.

OpenStack doesn't natively support integration with enterprise toolsets, but in lieu of this, it provides more standardized services. OpenStack feels and behaves more like a public cloud inside an enterprise and provides more flexibility to a user. As you can see in the following diagram, apart from VM provisioning, services such as database, image storage, and so on are also provisioned:

A private cloud with OpenStack

Please note that some of these services, which are provided as a part of the standard offering by OpenStack, can be also be orchestrated using commercial orchestrators. However, this will take some efforts in terms of additional automation and integration.